About this Add-on

This add-on sets S/MIME message security option "encrypt message", if valid X509 certificates are found for all of the recipients and for the sender himself. If these criteria are not matched, the option is not set.

You can disable confirmation message in the extension's options.

Change the default security/encryption setting in your account settings from "Required" to "Never (do not use encryption)" to let this add-on decide and encrypt only if possible.